Screw-in effect is one of the unintended phenomena that occurs during the root canal preparation with nickel-titanium rotary files. The aim of this study was to compare the screw-in effect among various nickel-titanium rotary file systems. Six different nickel-titanium rotary instruments (ISO 20/.06 taper) were used: K3 (SybronEndo, Glendora, CA, USA), Mtwo (VDW GmbH, München, Germany), NRT wit...

introduction: the aim of this study was to compare the formation of dentinal crack and craze lines in the root dentin during root canal preparation with three different niti endodontic systems, naming reciproc (rcp), protaper universal (ptu) and mtwo. methods and materials: one hundred extracted mandibular premolars with single canals were selected and decoronated. the teeth were randomly divid...

introduction: transportation is an important iatrogenic endodontic error which might cause failure. this study evaluated the canal transportation caused by neoniti and protaper instruments, using cone-beam computed tomography (cbct) cross sections. methods and materials: this in vitro experimental study was performed on 40 mesiobuccal roots of maxillary first molars. the teeth were scanned with...

PURPOSE The aim of this in vitro study of titanium abutments was to investigate the extent of treatment traces, the roughness depth, and the quantity of titanium or, in the case of coated abutments, titanium nitride (TiN) removed from the surface after treatment with various instruments. MATERIALS AND METHODS Eleven uncoated, mechanically smoothed abutments and 11 TiN-coated abutments were us...

PURPOSE The use of appropriate instruments to clean surfaces with minimal change, is critical for the successful maintenance of a dental implant. However, there is no consensus about the type and methodology for such instruments. The aim of this study was to characterize changes in the roughness of titanium surfaces treated by various scaling instruments. METHODS Thirty-seven identical disks ...

OBJECTIVES The aim of this study was to evaluate the sealing ability of lateral compaction and tapered single cone gutta-percha techniques in root canals prepared with stainless steel and rotary nickel titanium root canal instruments by fluid filtration method. STUDY DESIGN The root canals were prepared with stainless steel (SS) and nickel titanium (NiTi) instruments. The canals prepared with...

INTRODUCTION To improve the fracture resistance of nickel-titanium (NiTi) files, manufacturers have introduced new alloys and developed new manufacturing processes for the fabrication of NiTi files. This study aimed to examine the phase transformation behavior and microstructure of NiTi instruments from a novel controlled memory NiTi wire (CM wire). METHODS Instruments of EndoSequence (ES), P...

OBJECTIVES To evaluate modifications in root canal morphology following instrumentation with orifice openers using Computerized Tomography (CT). STUDY DESIGN Experimental in vitro study. A preoperative CT was performed on 49 molars to measure the root canal cross-sections. After preparing the canals with 6 different nickel-titanium (Ni-Ti) rotary system orifice opener type instruments and Gat...

Differences in mechanical properties between endodontic instruments might be related to the chemical composition, phase constitution, or fabrication process of nickel–titanium (NiTi) endodontic instruments. An awareness and knowledge of the mechanical properties of NiTi endodontic files and their association with the metallurgical properties is useful for clinicians to understand the behavior o...